Merge bitcoin/bitcoin#24836: add RPC (-regtest only) for testing package policy

e866f0d0666664885d4c15c79bf59cc59975887a [functional test] submitrawpackage RPC (glozow)
fa076515b07ac4b10b2134e323bf4f56be5996a8 [rpc] add new submitpackage RPC (glozow)

Pull request description:

  It would be nice for LN/wallet/app devs to test out package policy, package RBF, etc., but the only interface to do so right now is through unit tests. This PR adds a `-regtest` only RPC interface so people can test by submitting raw transaction data. It is regtest-only, as it would be unsafe/confusing to create an actual mainnet interface while package relay doesn't exist.

  Note that the functional tests are there to ensure the RPC interface is working properly; they aren't for testing policy itself. See src/test/txpackage_tests.cpp.

ACKs for top commit:
  t-bast:
    Tested ACK against eclair https://github.com/bitcoin/bitcoin/pull/24836/commits/e866f0d0666664885d4c15c79bf59cc59975887a
  ariard:
    Code Review ACK e866f0d0
  instagibbs:
    code review ACK e866f0d0666664885d4c15c79bf59cc59975887a

Tree-SHA512: 824a26b10d2240e0fd85e5dd25bf499ee3dd9ba8ef4f522533998fcf767ddded9f001f7a005fe3ab07ec95e696448484e26599803e6034ed2733125c8c376c84

2 files changed, 130 insertions, 5 deletions

diff --git a/test/functional/rpc_packages.py b/test/functional/rpc_packages.py
index 63533affd0..f687849287 100755
--- a/test/functional/rpc_packages.py
+++ b/test/functional/rpc_packages.py
@@ -15,16 +15,20 @@ from test_framework.messages import (
     CTxInWitness,
     tx_from_hex,
 )
+from test_framework.p2p import P2PTxInvStore
 from test_framework.script import (
     CScript,
     OP_TRUE,
 )
 from test_framework.util import (
     assert_equal,
+    assert_fee_amount,
+    assert_raises_rpc_error,
 )
 from test_framework.wallet import (
     create_child_with_parents,
     create_raw_chain,
+    DEFAULT_FEE,
     make_chain,
 )
 
@@ -51,7 +55,7 @@ class RPCPackagesTest(BitcoinTestFramework):
         self.address = node.get_deterministic_priv_key().address
         self.coins = []
         # The last 100 coinbase transactions are premature
-        for b in self.generatetoaddress(node, 200, self.address)[:100]:
+        for b in self.generatetoaddress(node, 220, self.address)[:-100]:
             coinbase = node.getblock(blockhash=b, verbosity=2)["tx"][0]
             self.coins.append({
                 "txid": coinbase["txid"],
@@ -82,7 +86,7 @@ class RPCPackagesTest(BitcoinTestFramework):
         self.test_multiple_parents()
         self.test_conflicting()
         self.test_rbf()
-
+        self.test_submitpackage()
 
     def test_independent(self):
         self.log.info("Test multiple independent transactions in a package")
@@ -132,8 +136,7 @@ class RPCPackagesTest(BitcoinTestFramework):
 
     def test_chain(self):
         node = self.nodes[0]
-        first_coin = self.coins.pop()
-        (chain_hex, chain_txns) = create_raw_chain(node, first_coin, self.address, self.privkeys)
+        (chain_hex, chain_txns) = create_raw_chain(node, self.coins.pop(), self.address, self.privkeys)
         self.log.info("Check that testmempoolaccept requires packages to be sorted by dependency")
         assert_equal(node.testmempoolaccept(rawtxs=chain_hex[::-1]),
                 [{"txid": tx.rehash(), "wtxid": tx.getwtxid(), "package-error": "package-not-sorted"} for tx in chain_txns[::-1]])
@@ -306,5 +309,127 @@ class RPCPackagesTest(BitcoinTestFramework):
         }]
         self.assert_testres_equal(self.independent_txns_hex + [signed_replacement_tx["hex"]], testres_rbf_package)
 
+    def assert_equal_package_results(self, node, testmempoolaccept_result, submitpackage_result):
+        """Assert that a successful submitpackage result is consistent with testmempoolaccept
+        results and getmempoolentry info. Note that the result structs are different and, due to
+        policy differences between testmempoolaccept and submitpackage (i.e. package feerate),
+        some information may be different.
+        """
+        for testres_tx in testmempoolaccept_result:
+            # Grab this result from the submitpackage_result
+            submitres_tx = submitpackage_result["tx-results"][testres_tx["wtxid"]]
+            assert_equal(submitres_tx["txid"], testres_tx["txid"])
+            # No "allowed" if the tx was already in the mempool
+            if "allowed" in testres_tx and testres_tx["allowed"]:
+                assert_equal(submitres_tx["vsize"], testres_tx["vsize"])
+                assert_equal(submitres_tx["fees"]["base"], testres_tx["fees"]["base"])
+            entry_info = node.getmempoolentry(submitres_tx["txid"])
+            assert_equal(submitres_tx["vsize"], entry_info["vsize"])
+            assert_equal(submitres_tx["fees"]["base"], entry_info["fees"]["base"])
+
+    def test_submit_child_with_parents(self, num_parents, partial_submit):
+        node = self.nodes[0]
+        peer = node.add_p2p_connection(P2PTxInvStore())
+        # Test a package with num_parents parents and 1 child transaction.
+        package_hex = []
+        package_txns = []
+        values = []
+        scripts = []
+        for _ in range(num_parents):
+            parent_coin = self.coins.pop()
+            value = parent_coin["amount"]
+            (tx, txhex, value, spk) = make_chain(node, self.address, self.privkeys, parent_coin["txid"], value)
+            package_hex.append(txhex)
+            package_txns.append(tx)
+            values.append(value)
+            scripts.append(spk)
+            if partial_submit and random.choice([True, False]):
+                node.sendrawtransaction(txhex)
+        child_hex = create_child_with_parents(node, self.address, self.privkeys, package_txns, values, scripts)
+        package_hex.append(child_hex)
+        package_txns.append(tx_from_hex(child_hex))
+
+        testmempoolaccept_result = node.testmempoolaccept(rawtxs=package_hex)
+        submitpackage_result = node.submitpackage(package=package_hex)
+
+        # Check that each result is present, with the correct size and fees
+        for i in range(num_parents + 1):
+            tx = package_txns[i]
+            wtxid = tx.getwtxid()
+            assert wtxid in submitpackage_result["tx-results"]
+            tx_result = submitpackage_result["tx-results"][wtxid]
+            assert_equal(tx_result, {
+                "txid": tx.rehash(),
+                "vsize": tx.get_vsize(),
+                "fees": {
+                    "base": DEFAULT_FEE,
+                }
+            })
+
+        # submitpackage result should be consistent with testmempoolaccept and getmempoolentry
+        self.assert_equal_package_results(node, testmempoolaccept_result, submitpackage_result)
+
+        # Package feerate is calculated for the remaining transactions after deduplication and
+        # individual submission. If only 0 or 1 transaction is left, e.g. because all transactions
+        # had high-feerates or were already in the mempool, no package feerate is provided.
+        # In this case, since all of the parents have high fees, each is accepted individually.
+        assert "package-feerate" not in submitpackage_result
+
+        # The node should announce each transaction. No guarantees for propagation.
+        peer.wait_for_broadcast([tx.getwtxid() for tx in package_txns])
+        self.generate(node, 1)
+
+
+    def test_submit_cpfp(self):
+        node = self.nodes[0]
+        peer = node.add_p2p_connection(P2PTxInvStore())
+
+        # 2 parent 1 child CPFP. First parent pays high fees, second parent pays 0 fees and is
+        # fee-bumped by the child.
+        coin_rich = self.coins.pop()
+        coin_poor = self.coins.pop()
+        tx_rich, hex_rich, value_rich, spk_rich = make_chain(node, self.address, self.privkeys, coin_rich["txid"], coin_rich["amount"])
+        tx_poor, hex_poor, value_poor, spk_poor = make_chain(node, self.address, self.privkeys, coin_poor["txid"], coin_poor["amount"], fee=0)
+        package_txns = [tx_rich, tx_poor]
+        hex_child = create_child_with_parents(node, self.address, self.privkeys, package_txns, [value_rich, value_poor], [spk_rich, spk_poor])
+        tx_child = tx_from_hex(hex_child)
+        package_txns.append(tx_child)
+
+        submitpackage_result = node.submitpackage([hex_rich, hex_poor, hex_child])
+
+        rich_parent_result = submitpackage_result["tx-results"][tx_rich.getwtxid()]
+        poor_parent_result = submitpackage_result["tx-results"][tx_poor.getwtxid()]
+        child_result = submitpackage_result["tx-results"][tx_child.getwtxid()]
+        assert_equal(rich_parent_result["fees"]["base"], DEFAULT_FEE)
+        assert_equal(poor_parent_result["fees"]["base"], 0)
+        assert_equal(child_result["fees"]["base"], DEFAULT_FEE)
+        # Package feerate is calculated for the remaining transactions after deduplication and
+        # individual submission. Since this package had a 0-fee parent, package feerate must have
+        # been used and returned.
+        assert "package-feerate" in submitpackage_result
+        assert_fee_amount(DEFAULT_FEE, rich_parent_result["vsize"] + child_result["vsize"], submitpackage_result["package-feerate"])
+
+        # The node will broadcast each transaction, still abiding by its peer's fee filter
+        peer.wait_for_broadcast([tx.getwtxid() for tx in package_txns])
+        self.generate(node, 1)
+
+
+    def test_submitpackage(self):
+        node = self.nodes[0]
+
+        self.log.info("Submitpackage valid packages with 1 child and some number of parents")
+        for num_parents in [1, 2, 24]:
+            self.test_submit_child_with_parents(num_parents, False)
+            self.test_submit_child_with_parents(num_parents, True)
+
+        self.log.info("Submitpackage valid packages with CPFP")
+        self.test_submit_cpfp()
+
+        self.log.info("Submitpackage only allows packages of 1 child with its parents")
+        # Chain of 3 transactions has too many generations
+        chain_hex, _ = create_raw_chain(node, self.coins.pop(), self.address, self.privkeys, 3)
+        assert_raises_rpc_error(-25, "not-child-with-parents", node.submitpackage, chain_hex)
+
+
 if __name__ == "__main__":
     RPCPackagesTest().main()
diff --git a/test/functional/test_runner.py b/test/functional/test_runner.py
index 6a44f9d21d..e68a963746 100755
--- a/test/functional/test_runner.py
+++ b/test/functional/test_runner.py
@@ -130,6 +130,7 @@ BASE_SCRIPTS = [
     'wallet_address_types.py --descriptors',
     'feature_bip68_sequence.py',
     'p2p_feefilter.py',
+    'rpc_packages.py',
     'feature_reindex.py',
     'feature_abortnode.py',
     # vv Tests less than 30s vv
@@ -231,7 +232,6 @@ BASE_SCRIPTS = [
     'mempool_packages.py',
     'mempool_package_onemore.py',
     'rpc_createmultisig.py',
-    'rpc_packages.py',
     'mempool_package_limits.py',
     'feature_versionbits_warning.py',
     'rpc_preciousblock.py',